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Fin structure formationRelated Patent Categories: Etching A Substrate: Processes, Etching And Coating Occur In The Same Processing ChamberFin structure formation description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20070170146, Fin structure formation. Brief Patent Description - Full Patent Description - Patent Application Claims
BACKGROUND OF THE INVENTION [0001] The present invention relates to the formation of semiconductor devices. More particularly, the invention relates to the formation of semiconductor devices with fin structures. [0002] In a semiconductor-based device (e.g., integrated circuits or flat panel displays), fin structures may be used in various devices. For example, a finFET is a MOSFET built on a SOI substrate on which silicon is etched into a fin shaped body of the transistor. A gate is wrapped around and over the fin structure. [0003] Spacer lithography may be one way of creating fins. In one way of doing this, a sacrificial layer is provided and then etched to form sacrificial structures. A conformal CVD is then used to form a conformal layer over and around the sacrificial structures. An etch back is used to etch the horizontal layers of the conformal layer. The sacrificial structure is then removed to form fin structures. The thickness of the fins may be 10 nm or less. To provide a desired conformal layer, the conventional CVD deposition may require a high temperature CVD. Such high temperatures may be detrimental to the semiconductor device. The high temperature may cause a process to go beyond a device thermal budget. In addition, if doping has previously been done, the high temperature may be detrimental to the doped areas. [0004] In addition, such CVD fin processes are limited with regards to the sacrificial layer and fin. Generally, a sacrificial layer of silicon oxide would provide a fin of silicon nitride. A sacrificial layer of silicon nitride would provide a sacrificial layer of silicon oxide. [0005] Furthermore, forming fin structures with conformal CVD processes places very stringent requirements on the profile of the sacrificial structures. The profile angle would need to be very close to vertical. A slight deviation from vertical profile would cause the fin structure to tilt, causing potential defect problems and CD variations. SUMMARY OF THE INVENTION [0006] To achieve the foregoing and in accordance with the purpose of the present invention, a method for forming fin structures is provided. Sacrificial structures are provided on a substrate. Fin structures are formed on the sides of the sacrificial structures. The forming of the fin structures comprises a plurality of cycles, wherein each cycle comprises a fin deposition phase and a fin profile shaping phase. The sacrificial structure is removed. [0007] In another manifestation of the invention, a method for forming a plurality of vertical fins on a substrate is provided. Sacrificial structures are provided on the substrate. Fin structures are formed on the sides of the sacrificial structures, comprising a plurality of cycles. Each cycle comprises a fin deposition phase, which deposits a fin material, and a fin profile shaping phase, which shapes the profile of the deposited fin material. The fin deposition phase comprises providing a deposition gas, forming a plasma from the deposition gas, depositing deposition material to form fins, and stopping the flow of the deposition gas. The fin profile shaping phase comprises providing a profile shaping gas different than the deposition gas, forming a plasma from the profile shaping gas, shaping the profile of the deposited deposition material, and stopping the flow of the profile shaping gas. The sacrificial structure is removed. [0008] In another manifestation of the invention, an apparatus for forming fin structures is provided. A plasma processing chamber comprising a chamber wall forming a plasma processing chamber enclosure, a substrate support for supporting a substrate within the plasma processing chamber enclosure, a pressure regulator for regulating the pressure in the plasma processing chamber enclosure, at least one electrode for providing power to the plasma processing chamber enclosure for sustaining a plasma, a gas inlet for providing gas into the plasma processing chamber enclosure, and a gas outlet for exhausting gas from the plasma processing chamber enclosure is provided. A gas source is in fluid connection with the gas inlet. The gas source comprises a sacrificial layer etchant source, a fin deposition gas source, and a fin profile shaping gas source. A controller is controllably connected to the gas source and the at least one electrode. The controller comprises at least one processor and computer readable media. The computer readable media comprises computer readable code for providing sacrificial structures on the substrate, computer readable code for forming fin structures on the sides of the sacrificial structures, comprising a plurality of cycles, and computer readable code for removing the sacrificial structure. The computer readable code for forming fin structures comprises computer readable code for providing a plurality of cycles, wherein each cycle comprises a fin deposition phase which deposits a fin material, comprising computer readable code for providing a deposition gas, computer readable code for forming a plasma from the deposition gas, computer readable code for depositing deposition material to form fins, and computer readable code for stopping the flow of the deposition gas, and a fin profile shaping phase which shapes the profile of the deposited fin material, comprising computer readable code for providing a profile shaping gas different than the deposition gas, computer readable code for forming a plasma from the profile shaping gas, computer readable code for shaping the profile of the deposited deposition material, and computer readable code for stopping the flow of the profile shaping gas. [0009] These and other features of the present invention will be described in more detail below in the detailed description of the invention and in conjunction with the following figures. BRIEF DESCRIPTION OF THE DRAWINGS [0010] The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which: [0011] FIG. 1 is a high level flow chart of a process that may be used in an embodiment of the invention. [0012] FIG. 2 is a more detailed flow chart of the forming sacrificial structures. [0013] FIGS. 3 A-F are schematic cross-sectional and top views of a stack processed according to an embodiment of the invention. [0014] FIG. 4 is a schematic view of a plasma processing chamber that may be used in practicing the invention. [0015] FIGS. 5 A-B illustrate a computer system, which is suitable for implementing a controller used in embodiments of the present invention. [0016] FIG. 6 is a more detailed flow of a step of fin formation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0017] The present invention will now be described in detail with reference to a few preferred embodiments thereof as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well known process steps and/or structures have not been described in detail in order to not unnecessarily obscure the present invention. [0018] To facilitate understanding, FIG. 1 is a high level flow chart of a process that may be used in an embodiment of the invention. Sacrificial structures are formed (step 104). Fins are formed on the side of the sacrificial structures (step 108). FIG. 6 is a more detailed flow chart of the forming fins on the side of the sacrificial structures, which comprises a plurality of cycles, wherein each cycle comprises a fin deposition phase (step 604) and a fin profile shaping phase (step 608). The sacrificial structures are removed (step 112). EXAMPLE 1 [0019] In an example of an embodiment of the invention, the sacrificial structures are formed (step 104). FIG. 2 is a more detailed flow chart of the formation of the sacrificial structures. A sacrificial layer is formed (step 204). FIG. 3A is a cross-sectional view of a stack 300 with a sacrificial layer 312 formed over a substrate 304. One or more layers such as an intermediate layer 308 may be between the sacrificial layer 312 and the substrate 304. In this example, the substrate 304 is a silicon wafer. The sacrificial layer may be of a wide assortment of materials such as silicon nitride (SiN), photoresist, silicon oxide (SiO.sub.2), amorphous carbon, silicon, or organic material. The sacrificial layer is silicon carbide. In other embodiments, the sacrificial layer is at least one of SiC, SiN, SiOC, H doped SiOC, TiN, TaN, Ti, Ta, Si, and SiO2. More generally, the sacrificial layer is of any material, which may be selectively etched with respect to a fin material and any underlying layer. Continue reading about Fin structure formation... Full patent description for Fin structure formation Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Fin structure formation patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Fin structure formation or other areas of interest. ### Previous Patent Application: Method of manufacturing a display substrate Next Patent Application: Etching method and method of fabricating opening Industry Class: Etching a substrate: processes ### FreshPatents.com Support Thank you for viewing the Fin structure formation patent info. 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